49. An ideal gas undergoes an irreversible process from its initial state (Pi, Vi, Ti) to
its final state (Pf, Vf, Tf). Which of the following statements is true?
(A) The change in the entropy of the gas is not well defined since it is an
irreversible process.
(B) The change in the entropy is well defined and will increase when Vf > Vi.
(C) The change in the entropy is well defined and will increase when Pf > Pi.
(D) The change in the entropy is well defined and will increase when Tf > Ti.
(E) None of the above.